Provide tools for finding multiple-objective optimal designs for
estimating the shape of dose-response, the ED50 (the dose producing an effect
midway between the expected responses at the extreme doses) and the MED (the
minimum effective dose level) for the 2,3,4-parameter logistic models and for
evaluating its efficiencies for the three objectives. The acronym VNM stands
for V-algorithm using Newton Raphson method to search multiple-objective
optimal design.